Halocarbon oil greases



Patented June 8, 1954 k. HALOCARBON OIL GREASES Arnold J. Morway,

Clark Township,

Union County, David W. Young, Westfield, and Delmer L. Cottle, Highland Park, N. J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application October 3, 1951, Serial No. 2519,6365

6 Claims. 1

This invention relates to novel lubricating grease compositions. Particularly the invention relates to lubricating grease compositions prepared without the use of ordinary grease forming soaps. More particularly the invention relates to acid and alkali resisting greases prepared by thickening a halocarbon oil with an N-acyl paraaminophenol.

Lubricating engineers have long recognized the need for a lubricating grease composition which does not contain ash-forming soaps. There are many industrial uses for lubricating greases which will not leave deposited upon bearing surfaces the highly corrosive and friction-increasing soap residues left when the grease base has become completely volatilized.

There has recently been presented to the art a series of halocarbon oils which are becoming increasingly important in the field of lubricating engineering. This is due partly to the fact that these new halocarbon oils are completely resistant to the efiect of acids and alkalis, as well as oxidizing agents, either Wet or dry, and are unaliected by prolonged heating at temperatures as high as 480 F. some of these new halocarbon oils are described in United States Patents Nos. 2,435,205, 2,435,206, 2,467,1i5 and 2,515,115.

Exemplary of these halocarbon oils are the polymers of chiorotrifluoroethylene. This chlorofiuorinated hydrocarbon is polymerized by a process involving the use of a peroxide type cata- I lyst such as benzoyl peroxide, an inert solvent typified by chloroform, and a stabilizing material exemplified by cobalt trifluoride. The polymerication is straightforward and the polymeric materials range in molecular weight from about 500 to about 1300.

lhese polymers of chlorotrifluoroethylene may be graphically illustrated by the following formula:

F n- R wherein R and R are selected from the grouping consisting oi 01, F, and CFzCl and n is an integer between about 4 and 12.

As these polymeric materials increase in molecular weights, their appearance changes from a light oil through a heavy oil to a petrolatum-like substance and finally at high molecular weights a wax-like material.

It has now been found that these halocarbon I 'The novel grease compositions in accordance with the instant invention have the advantage or" leaving no soap residueson the bearing surfaces and of being resistant to the reaction of acids, alkalis, salts, or oxidizing agents. They are also resistant to moisture and are unafiected by heating to a high temperature. In addition, the greases of this invention are completely reversible, that is to say, the grease structure of the new lubricating compositions is not lost when the melting point is reached but rather on recrystallization the thickening agent crystals redisperse to again form a stable grease structure.

The N-acyl amino phenols useful to form the non-soap grease compositions of this invention have the following general formula:

H 0 HO N-d n I RI! wherein R is an hydrocarbon group containing from 14 to 22 carbon atoms, preferably an alkyl group which is Wholly non-benzenoid, and wherein R and R." are hydrogen atoms or alkyl groups containing from 1 to 20 carbon atoms.

The preferred embodiment of this invention contemplates the use of compounds, according to the formula above, wherein R. and R are hydrogen atoms and wherein R. is a straight chain aliphatic group containing from 14 to 22 carbon atoms. Exemplary of these preferred compounds are N-palmitoyl p-amino phenol, N-stearoyl p-amino phenol, and N -arachidoyl p-amino phenol, N-behenoyl p-amino phenol with the N- stearoyl or N-palmitoyl p-amino phenol or mixtures thereof being especially preferred.

The alkylated acyl p-amino phenols exemplified by the formula above when R and R are alkyl groups containing from 1 to 20 and preferably from s to 15 carbon atoms, are also operable as lubricating oil thickeners. Compounds such as N-n-valeryl-4= -amino-3-pentadecyl phenol, (N-npentanoyll-amino-3-pentadecyl phenol), N-npropanoyl-el-amino-3-pentadecyl phenol, N-npentanoyl 4 amino-2,6,di-tert.-butyl phenol, N-n-hexyl-4-amino-2-hexyl phenol, are examples of the alkylated acyl p-amino phenols which are operable.

The preparation of these acyl p-aminophenols isaccomp'lishe'd by simply admixing the desired acid or acid chloride with the desired p-amino phenol and heating the mixture under proper reaction conditions. The reaction progresses smoothly, (splitting off water or hydrogen chloride) giving the desired amino phenol which may be purified by any of the various methods known to the art such as distillation, crystallization, extraction, etc.

To prepare the lubricating grease compositions of this invention the desired acyl p-amino phenol is admixed with the halocarbon oil in proportions varying from about 1% to about 10% by weight of the phenol to 99% to 90% by weight of the halogenated compound. The temperature is then raised to the melting point of the phenol and allowed to cool to room temperature wherein the process of cooling the acyl amino phenol recrystallizes in a dispersed state and causes the formation of a stable grease structure.

The instant invention will be more clearly explained by reference to the following examples:

Example I One mol of p-amino phenol was placed in a glass round-bottomed flask fitted with a reflux condenser with an azeotropic takeoff arm. There was added to the flask one mol of stearic acid and about 150 cc. of xylene. The xylene served as an entraining agent for the Water formed during the course of the reaction. The flask was then heated to the xylene reflux temperature and kept at that temperature for about 9 hours, or until 86% of the theoretical water (1 mol) had been removed. The contents of the flask were then emptied into an evaporating dish and heated on a steam bath until the last trace of xylene was removed. The product was then recrystallized from glacial acetic acid and there resulted a yield of 78% theoretical of colorless N-stearoyl p-amino phenol, melting point 132 C. Analysis for nitrogen was 3.75%, compared to a calculated 3.78%.

Example II 2% of N-stearoyl-p-amino phenol prepared in accordance with the procedure of Example I above was admixed with a polymer of chlorotrifluoroethylene having a viscosity at 100 F. of 4.97 centistokes, a density of 1.878 and a molecular weight of approximately 550. The mixture was heated to about 250 F. while stirring and allowed to cool. a smooth grease-like appearance. It was sub mitted to the standard grease inspection tests and gave the following results:

Consistency: mm./10 AS'I'M unworked penetration (at 77 ASTM worked penetration (60 strokes) 275 Worked penetration (1000 strokes fine hole worker plate 279 Dropping point236 F. Solubility in boiling waternil.

1 325-4 diameter holes.

Example III Ercample IV A polymer of chlorotrifiuoroethylene having a melting point of 178 F. and a density at 210 F. of 1.89 had the appearance of a white wax. 98%

The resulting composition had The worked ASTM penetration of of this polymeric material was blended with 2% by weight of N-stearoyl p-amino phenol by heating to about 250 F. while stirring and was allowed to cool. The resulting composition gave the appearance of a solid grease structure. The dropping point of this composition was 240 F.

though the above examples are given of preparing novel greases with the chlorotrifluoroethylene polymer type of the halocarbon oils, it will be understood that any of the known halocarbon oils may be used and those described in the above identified patents are particularly well suited.

To summarize briefly, this invention relates to novel lubricating grease compositions having outstanding characteristics which are prepared by thickening to a grease consistency a material represented by the general formula wherein R, and R are selected from the grouping consisting of Cl, F, and CFzCl and n is an integer of from 4 to 12 with an N-acyl p-amino phenol having the general formula wherein R. is an alkyl group containing from 14 to 22 carbon atoms, and wherein R and R" are hydrogen atoms or alkyl groups containing from 1 to 20 carbon atoms. From 1 to 10% by weight of the amino phenol is used, preferably 1.5% to 5% by weight. The new lubricating grease compositions have the advantages of leaving no ashforming soap residues upon volatilization, of being completely resistant to attack from alkalis, acids, salts, or oxidizing agents and of being unaiTected by prolonged heating at a high temperature.

What is claimed is:

1. A lubricating grease composition consisting essentially of a polymer of chlorotrifluoroethylene thickened to a grease consistency with from 1% to 10% by weight of a compound having the general formula wherein R is a non-benzenoid hydrocarbon group having from 14 to 22 carbon atoms and wherein R and R are selected from the class consisting of hydrogen and alkyl groups containing from 1 to 20 carbon atoms.

2. A lubricating grease composition according to claim 1 wherein said compound of the formula is N-stearoyl p-amino phenol.

3. A lubricating grease composition consisting essentially of a polymer of chlorotrifiuoroethylene thickened to a grease consistency with from 1% to 10% by weight of a material having the general formula wherein R is a non-benzenoid hydrocarbon group having from 14 to 22 carbon atoms and wherein R and R" are selected from the class consisting of hydrogen and alkyl groups containing from 11 to 20 carbon atoms.

4. A lubricating grease composition consisting essentially of a polymer of chlorotrifiuoroethylene thickened to a grease consistency with from 1% to 10% by weight of a material having the general formula 6. A lubricating grease composition according to claim 3 wherein R is a hydrocarbon group having 18 carbon atoms per molecule.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,467,145 Morway et a1 Apr. 12, 1949 2,467,146 Morway Apr. 12, 1949 2,477,311 Morway July 26, 1949 2,510,112 Hoebrook June 6, 1950 2,549,580 Denison et a1. Apr. 17, 1951 2,604,452 Morway et a1 July 22, 1952 OTHER REFERENCES Low Polymers of Chlortrifiuorethylene, Miller et al. in I. and E. Chemistry, vol. 39, No. 3, pages 333 to 337. 

1. A LUBRICATING GREASE COMPOSITION CONSISTING ESSENTIALLY OF A POLYMER OF CHLOROTRIFLUOROETHYLENE THICKENED TO A GREASE CONSISTENCY WITH FROM 1% TO 10% BY WEIGHT OF A COMPOUND HAVING THE GENERAL FORMULA 